The US Air Force’s (USAF’s) Lockheed Martin F-35 and F-22 stealth fighters passed data to one another using a communications gateway aboard a Lockheed U-2 spyplane.

The F-35’s Multifunction Advanced Data Link (MADL) and the F-22’s Intra-Flight Data Link are incompatible, so the two aircraft types cannot transmit data to each other.

USAF F-35A

Source: US Air Force

US Air Force F-35A stealth fighter

To get around that problem, the USAF, Missile Defense Agency and Lockheed used an “Open Systems Gateway” communications payload aboard a U-2 to pass data between one F-22 and five F-35s, Lockheed said on 3 May. The gateway also allowed the stealth aircraft to share data with units on the ground. And, target tracks were transmitted by and through the U-2 into the fighters’ avionics and pilot displays, the company says.

“Project Hydra marks the first time that bi-directional communications were established between fifth-generation aircraft in-flight, while also sharing operational and sensor data down to ground operators for real-time capability,” says Jeff Babione, vice-president of Lockheed Martin Skunk Works, the company’s advanced research and development division. “This next-level connectivity reduces the data-to-decision timeline from minutes to seconds, which is critical in fighting today’s adversaries and advanced threats.”

The airborne gateway also allowed the F-35 for the first time to pass sensor data to a ground system over a Tactical Targeting Network Terminal (TTNT) link, says Lockheed. The TTNT is an ad hoc mesh network, a sort of temporary communications network between in-range aircraft that allows any node to act as a relay for information.

Using the TTNT, data from the F-35 was sent to a US Army Integrated Battle Command System, a command centre for tracking missiles and aircraft. The command centre used the data to orchestrate a simulated “army fires exercise”, likely meaning a virtual ballistic missile or artillery strike.

In December, the USAF demonstrated an F-35A and F-22 exchanging data for the first time using a ground-based gatewayONE system, which is designed to translate between their two different communications systems. Also, as part of that demonstration, a gatewayONE aboard a Kratos XQ-58A Valkyrie unmanned air vehicle was supposed to facilitate the airborne of exchange of data, but failed due to technical issues.

The USAF and other military services are trying to develop ways to share information between one another and across different military equipment. By quickly passing battlefield information between different vehicles, such as aircraft, ships and artillery, the Department of Defense believes it can outthink, outmanoeuvre and then overwhelm its adversaries.